A relationship exists between the physical and optical properties of an IC device and the information from light shined on the IC device by instruments such as an ellipsometer and a scatterometer. The physical and optical properties of a wafer are highly sought after by chip manufacturers, since microchip fabrication machinery can be tuned and optimized once these parameters are known, preferably through non-destructive techniques that operate in real time.
Unfortunately, during wafer fabrication tremendous quantities of data are produced that cannot readily be used by a chip manufacturer to control processes in real-time.
The present invention addresses the concern of quickly turning raw data into information in microchip fabrication, using cluster analysis, a technique of multivariate analysis that creates degrees of association between items and the groups assigned to the items.